ReFaey, Karim

OBJECTIVE The implementation of robotics and spinal anesthesia (SA) in spine surgery is rapidly expanding, offering significant benefits for an increasingly complex and aging patient population with degenerative spinal disease. Here, the authors present the largest cohort to date evaluating the combined use of these two techniques in minimally invasive (MIS) transforaminal lumbar interbody fusion (TLIF). METHODS The authors retrospectively analyzed surgical outcomes of a series of patients who underwent robot-assisted (RA)–MIS TLIF under SA and general anesthesia (GA) at their institution from 2018 to 2024. Primary outcomes included operative times and postoperative pain intensity. Secondary outcomes included estimated blood loss, intraoperative complications, postoperative functional status, length of stay (LOS), and discharge status. To address potential confounders, a 1:1 propensity score–matching and regression analysis was implemented. Statistical analyses were conducted using Python. RESULTS A total of 209 patients underwent RA-MIS TLIF, with 31 (14.83%) receiving SA and 178 (85.17%) GA. After propensity score matching, the SA cohort demonstrated significantly shorter median total operating room (OR) time, total procedure time, time from entering the OR to skin incision, and time from closure to leaving the OR (all p < 0.01). Additionally, postoperative pain scores were significantly lower (p < 0.01), and LOS was significantly shorter (p < 0.01) in the SA cohort. Regression analysis, adjusting for potential confounders, further supported these findings. CONCLUSIONS RA-MIS TLIF fusion under SA is a safe and effective approach that significantly reduces operative time, postoperative pain, and hospital LOS in patients undergoing surgery for degenerative lumbar spine disease.

Abstract Spontaneously arising canine high-grade gliomas (cHGG) offer a clinically relevant model for human glioblastoma, sharing conserved histopathological, genetic, and immunological traits. We established two cHGG cell lines and two canine adipose-derived mesenchymal stem cell (cAMSC) lines, and immune-competent 3D cHGG organoid models. Immunoblotting of cHGG cell lines showed that these models exhibit hallmark GBM features including SOX2, Nestin, GFAP, and activation of PI3K/AKT and p53 pathways. Given the established cytotoxic and differentiation-inducing effects of BMP4 in human GBM cell lines, we evaluated whether our canine glioma models recapitulate these responses to assess their translational relevance. BMP4 treatment of cHGG cells induced significant cytotoxicity and reduced migration, accompanied by downregulation of SOX2 and Nestin, upregulation of GFAP, and suppression of CDK6 and phospho-AKT—hallmarks of reduced stemness and astrocytic differentiation. In human-derived GBM cells, BMP4 enhanced radiosensitivity, likely via differentiation and depletion of therapy-resistant stem-like populations. Our cHGG models mirrored these molecular responses, suggesting a conserved BMP4 signaling axis in canine glioma. Quantitative phase imaging showed that BMP4 treatment was non-toxic to cAMSCs and did not impair their migration, supporting the feasibility of engineering cAMSC-BMP4 for therapeutic delivery. Observed molecular traits in canine and human gliomas—including mutually exclusive mutations in PDGFRA and PIK3CA, and shared expression of TP53, PTEN, p21, Rb1, mTOR, and MAPK—underscore the translational relevance of the cHGG model. High-content imaging further confirmed expression of p-AKT, p53, MDM2, and CD44 in cHGG lines, reinforcing activation of conserved gliomagenic pathways. To complement these findings, we developed a cHGG 3D organoids from freshly resected tumors, that recapitulate tumor heterogeneity with co-localized GFAP+/Nestin+ glioma cells, CD3+ infiltrating T cells, macrophages and cleaved caspase-3+ apoptotic cells, indicating active immune surveillance and ongoing programmed cell death. Our results support canine GBM model as a platform to assess glioma biology, cell therapy, and modeling immune engagement in a species-relevant, physiologically intact environment for streamlined translation of therapeutics to human clinical trials.

Abstract Glioblastoma is an aggressive brain cancer with poor prognosis. Recent evidence implicates metabolic reprogramming, including the hexosamine biosynthetic pathway (HBP) and pentose phosphate pathway (PPP), as critical for tumor survival, therapy resistance, and progression. HBP inhibition with a proprietary small molecule (G2Bz) reduced stemness and migration and increased apoptosis of GBM in vitro. HBP inhibition was concomitant with an accumulation of metabolites in the Pentose Phosphate Pathway (PPP). Therefore, we further inhibited HBP with G2Bz and/or PPP with 6-aminonicotinamide (6-AN) in primary patient-derived GBM lines and evaluated additive or synergistic effects. Ultrastructural and functional changes were examined by electron microscopy (EM), high content imaging of endoplasmic reticulum (ER) and lipid droplets (LD), extracellular-flux analysis, and lipid profiling. Synergism was validated in an orthotopic model receiving lipoparticle-encapsulated G2Bz via intranasal delivery and/or intraperitoneal 6-AN; tumor burden was monitored via bioluminescence. Dual inhibition of HBP/PPP revealed additive or synergistic anti-proliferative effect. EM displayed severe ultrastructural cell damage with mitochondrial disorganization, ER dilation, and cytoskeletal remodeling. These changes coincided with increased ROS generation and reduced spare respiratory capacity suggesting higher sensitivity and lower ability to fight stress. Reduced ER–mitochondria contacts accompanied by increased expression of BiP and ER expansion suggest an unfolded protein response. Loss of LDs were associated with downregulation of lipid biosynthesis regulator SREBF1 and an increase in free fatty acids with a rise in lipid peroxidation. Reduced mitochondria–LD contacts correlate with lower endogenous fatty acid oxidation and a shift to exogenous fatty acid utilization. Dual inhibition in-vivo, suppressed tumor growth compared to control. These findings support that dual inhibition of HBP/PPP synergistically disrupts tumor metabolism, promoting organelle disorganization and lipid remodeling and highlight metabolic co-targeting as a strategy to impair GBM metabolism.

Abstract BACKGROUND CNS ependymal tumors rarely demonstrate mixed subependymal and ependymal pathology. The clinical course of these tumors is difficult to predict, but prior studies have identified TERT mutations and loss of chromosome 6 as poor prognostic factors in these tumors when located in the posterior fossa. METHODS In this retrospective single-institution study, patients with a diagnosis of mixed subependymoma/ependymoma were identified and chart reviewed to describe demographics, pathological findings, treatment courses and clinical outcomes. RESULTS Eleven patients (median age 57, 2 female, 9 male) were identified. Ten tumors were in the posterior fossa and 1 in the cervical spine. At diagnosis, 2 underwent gross total resection, 8 underwent subtotal resection, and 1 was only biopsied. Radiotherapy was administered to 5 patients at initial diagnosis (54Gy in 30 fractions). Systemic therapy (temozolomide and bevacizumab) was administered at recurrence to 2 patients. Loss of chromosome 6 was present in 5 /11 patients and TERT mutations were present in 4/11 patients, with both present in 3/11 patients. Median progression-free survival (mPFS) was 90.1 months (95% CI: 90.1–NA), with 3 progression events observed at 22, 90, and 107 months. Median follow-up duration was 27.9 months. Receiving radiotherapy had a longer mPFS (98 vs 22 months, p=0.15), although non-significant. At the time of data cut-off none of the patients were deceased. CONCLUSIONS Mixed subependymoma/ependymoma is a rare diagnosis with varying clinical outcomes. Our case series demonstrated that the majority of patients did not exhibit the previously identified poor prognostic factors. Although non-significant due to limited case numbers, radiotherapy was suggestive of longer mPFS.

Abstract High-grade gliomas (HGGs) are aggressive, infiltrative brain tumors with poor survival outcomes and limited therapeutic options. Their spatial and molecular heterogeneity necessitates large, well-curated datasets integrating imaging, clinical, and genomic information to enable precision medicine and drive novel treatment development. Using the Medtronic StealthStation neuronavigation system, we collected over 1,000 spatially localized intraoperative biopsy samples from more than 250 patients undergoing resection for glioma at Mayo Clinic and partnering sites. Each biopsy site was recorded with 3D coordinates, labeled in real time, flash-frozen, and annotated with metadata including collection time, anatomical location, and surgical plan. Samples were processed and entered into a secure database along with the corresponding sampling coordinates, frozen pathology, whole-exome and RNA sequencing data, 5-ALA fluorescence status, patient demographics, and T1, T1Gd, T2, and T2-FLAIR MRI. This multimodal dataset supports radiogenomic research by enabling precise mapping of imaging features to molecular characteristics. A subset of this data, including 268 biopsies from 52 patients (25 male, 27 female) with reported intraoperative 5-ALA fluorescence, was used to develop a radiomics model predicting locoregional patterns of 5-ALA positivity based on preoperative MRI. Image features were extracted from the biopsy sample coordinates across multiple MRI sequences and paired with corresponding 5-ALA fluorescence status to train the model for regional fluorescence prediction. The final model achieved 83% accuracy on the training set and 86% on the validation set using a 70-15-15 data split; this included 208 samples for training and 42 for validation, stratified by patient to ensure no overlap of samples from the same individual across sets. These findings demonstrate the feasibility of predicting 5-ALA fluorescence using radiomic features from standard preoperative MRI, offering a promising noninvasive strategy for improving intraoperative decision-making and enabling more precise, personalized resections in patients with high-grade gliomas.

Abstract BACKGROUND High grade astrocytoma with piloid features (HGAP) is a newly recognized tumor with a distinct DNA methylation profile. Its clinical course, treatment response, and outcomes remain poorly understood. METHODS We conducted a retrospective cohort study across three Mayo Clinic sites including adults with a HGAP diagnosis confirmed by DNA methylation profiling. RESULTS 17 patients were included (median age 38 years, Q1, Q3: 29–59; 9 male). DNA methylation-based tumor classification using the NCI/Bethesda classifier (v2) indicated a match to HGAP with high confidence (calibrated score &gt;0.9) in 14 cases and was suggestive in 3 cases. All had MAPK pathway alterations (NF-1 mutation in 11, FGFR1 mutation in 2, KIAA1549::BRAF fusion in 2, FGFR1 transcript variant suggestive of internal tandem duplication in 1, KANK2::NTRK2 fusion in 1). All tumors also had CDKN2A/B homozygous deletion and 9 lost ATRX expression. Tumors were infratentorial (n=8), supratentorial (n=7), and spinal (n=2) at initial presentation. First line treatment included surgery followed by chemoradiation with temozolomide (n=12), surgery followed by radiation (n=4), radiation alone (n=1), and surgery alone (n=1). Gross total resection was achieved in 3/17, 8/17 had subtotal resection and 5/17 had biopsy. 14/17 received a median RT dose of 5700 cGy (range, 4005–6000) in 30 fractions. The median follow-up duration was 34.9 months. 8 patients experienced disease progression. The median progression-free survival (mPFS) was 30.3 months (95% CI: 15.4–NR). 6/8 underwent surgery; 3/8 underwent RT. Systemic therapies were administered in 5/8 (lomustine, bevacizumab, pembrolizumab, temozolomide, trametinib, tovorafenib). 3/17 patients died due to progressive disease with an OS of 54.2, 94.6 and 17.4 months, respectively. The mOS for the whole cohort was 54.2 months (95% CI: 54.2-NR). CONCLUSION While the optimal management of this newly recognized entity has yet to be established, our cohort demonstrates a clinical behavior consistent with CNS WHO grade 3, aligning with current WHO interpretations.

Abstract Glioblastoma (GBM) is the most common malignant tumor of the CNS, accounting for 80% of brain tumors. Recent advances in gene editing and immunology have led to the development of chimeric antigen receptors (CARs), including CARs incorporating chlorotoxin (CLTX) receptor domains for GBM targeting. While CAR-engineered neutrophils have shown promise, their systemic administration can induce severe off-target effects. Extracellular vesicles (EVs), secreted by these cells, retain properties of their parent cells—including CAR expression and tumor-lytic activity—yet their potential has not been explored in CAR Neutrophils. To address this, CAR-CLTX DNA was inserted into the AAV1 safe harbor locus of induced pluripotent stem cells, which were subsequently differentiated into neutrophils. Conditioned media were collected during differentiation and processed using extraPEG-based EV isolation. EVs were quantified via nanoparticle tracking analysis, electron microscopy, and western blotting. Proteomic and microRNA (miRNA) profiling of EV cargo was conducted at days 12 and 21 of differentiation. Cytotoxic effects of EVs were assessed in U87MG and LN229 glioblastoma cells in 2D culture, 3D organoids, and in vivo models. EVs were secreted in high quantities within the 100–200 nm size range, expressed canonical exosomal markers, and exhibited characteristic morphology. Proteomic analysis identified neutrophil-associated proteins involved in migration, chemotaxis, and degranulation. miRNA sequencing revealed high levels of tumor-suppressive miRNAs (e.g., miR-182) implicated in apoptotic signaling, T cell receptor pathways, cytokine-cytokine receptor interactions, Jak-STAT, Hedgehog, and NK cell-mediated cytotoxicity. EV uptake by glioma cells was demonstrated in vitro. Cytotoxic effects of CAR Neutrophil EVs were observed across glioblastoma cell lines, organoids, and in vivo. These findings demonstrate that CAR Neutrophil-derived EVs carry anti-tumor protein and miRNA cargo, are efficiently taken up by GBM cells, and mediate glioma cell cytotoxicity. This supports the feasibility of correlating EV cargo composition with function in GBM treatment.

ABSTRACT Glioblastoma (GBM), the most aggressive primary brain tumour in adults, presents significant challenges due to its universal recurrence and limited survival rates. A key driver of GBM progression is the subpopulation of brain tumour‐initiating cells (BTICs), which contribute to therapy resistance and interact with the tumour microenvironment, particularly the cellular components in the subventricular zone (SVZ). Extracellular vesicles (EVs) are critical mediators of intercellular communication, carrying bioactive molecules, such as proteins and RNAs, that can modulate the behaviour of recipient cells. This study investigates the role of EVs in GBM's communication with non‐cancer cells. We utilised the proximity‐labelling system TurboID to achieve global and unbiased labelling of proteins within GBM‐derived EVs. By inducing TurboID expression in primary‐cultured human BTICs from GBM patients, we achieved efficient biotinylation of EV proteins without compromising vesicle integrity, and performed proteomic analysis of biotinylated proteins, which revealed a diverse cargo within BTIC‐EVs. Our method marks the first implementation of TurboID for unbiased global labelling of EV protein cargo in primary cells. This approach facilitates the investigation of EV‐mediated communication and potential therapeutic targets, contributing to the understanding of GBM's complex interactions with the brain's microenvironment and identification of biomarkers for improved diagnosis and treatment response.

Abstract Purpose Cenobamate is approved for treating focal epilepsy and has potential for treating tumor‐related epilepsy (TRE) based on potential anti‐tumor effects, though there is little data on efficacy and safety in this patient population. Methods This was a retrospective, multi‐center study of patients with TRE who were prescribed cenobamate as adjunctive treatment between January 2020 and November 2024 at Mayo Clinic in Florida, Minnesota, and Arizona. Drug efficacy was assessed, and factors that were predictive of response to treatment were analyzed. Results A total of 17 patients were included, with 12 being drug resistant. The median seizure frequency for the entire group before starting cenobamate treatment was 12 (IQR = 4–64) per month, and after treatment at last follow‐up was 3 (IQR = 1–15) per month, with an overall 56.3% reduction. Four patients (23.5%) were seizure‐free, and 7 (41.1%) patients were responders (at least 50% seizure reduction). No adverse events were reported for patients on concurrent chemotherapy. Responders had significantly fewer seizures per month compared to non‐responders (5.72 ± 10.29 vs. 27.33 ± 30.17; p = .030). No clinical factors were predictive of responsiveness (or lack thereof) to cenobamate. Conclusions This study demonstrates that adjunctive therapy with cenobamate treatment for TRE is a feasible and potentially effective option. Clinical history, including drug resistance, did not predict drug efficacy. No adverse effects were reported in those treated with chemotherapy. Further studies are needed to validate treatment response and safety.